FNZ 68 - Simuliidae (Insecta: Diptera) - Introduction
Craig DA, Craig REG, Crosby TK 2012. Simuliidae (Insecta: Diptera). Fauna of New Zealand 68, 336 pages.
(
ISSN 0111-5383; no. 68 (print),
ISSN 1179-7193 (online)
;
no.
68.
ISBN 978-0-478-34734-0 (print),
ISBN 978-0-478-34735-7 (online)
).
Published 29 June 2012
ZooBank: http://zoobank.org/References/9C478D54-FEB2-45E8-B61C-A3A06D4EB45D
Introduction
The Maori call Simuliidae “namu” (Polack 1838) and one legend, as given at Milford Sound, lays responsibility for Te Namu on Hinenuitepo , goddess of the underworld. As she gazed at the beauty crafted by Tuterakiwhanoa, the carver of Fiordland, she was fearful that humans would not want to leave such a paradise. Te Namu were to remind humans of their mortality and not linger. Miller (1952a) detailed Maori use of the word “namu” and its variants, such as “namu katipo ” for mosquitoes (more commonly called waeroa — literally “long legs” or “the long-legged one”), and “naonao” for midges or small moths. In French Polynesia “no-no” or “nono” refers to bloodsucking simuliids. Maori legend has it that the mosquito advised the namu (simuliids) to wait until dark before biting — advice that was not taken.
Characterisation of the family Simuliidae
The family Simuliidae is a relatively small family of flies with only some 2 100 extant species described (Adler & Crosskey 2012). The genus Austrosimulium now comprises some 30 species with 19 recognised in the New Zealand subregion. Because of their economic and medical importance Simuliidae have been the focus of major investigations and reviews, and worldwide much is known (e.g., Strickland 1911; Puri 1925; Grenier 1949; Dinulescu 1966; Rivosecchi 1978; Laird 1981; Kim & Merritt 1988; Rubtsov 1989; Crosskey 1990; Takaoka 2003; Adler et al. 2004). The works by Crosskey and Adler et al. are recommended for detailed general introductions to the family.
Simuliidae are in large part characterised by shape of the adult. The body is compact with a distinct arched thorax (Fig. 1), thence the common name of “buffalo flies” in some parts of the world. The wings are broad with heavy anterior venation (Fig. 2, 3). As Adler et al. (2004) noted, this gestalt is ancient and known to be at least 94–90 million years old. While adults of the family are notoriously morphologically homogeneous and generally of dark colour (hence “black flies”), some are multi-coloured. The pupal stage is also generally uniform across the family and reflects the shape of the adult (Fig. 4). The prothoracic spiracular gills (respiratory organs) are amongst the most diverse structures in the family and are heavily used for diagnostic characters. The larvae (Fig. 6) have a well sclerotised head capsule, and the body is elongated and usually dumbbell-shaped. In most simuliids the head supports a pair of distinctive labral fans. There is a single anterior proleg and one posteriorly, both with hooks. Again, this body form is ancient, shown by superb fossils from the Australian Lower Cretaceous (138 million years ago) (Jell & Duncan 1986).
Systematically, Simuliidae are included in the infraorder Culicomorpha, a well-supported clade within the paraphyletic “Nematocera” or lower Diptera (Yeates & Wiegmann 2005). The Culicomorpha encompasses 2 superfamilies, with Culicoidea including Culicidae (mosquitoes), Dixidae (meniscus midges), and Corethrellidae (frog-biting midges), and its sister taxon the Chironomoidea comprising the Thaumaleidae (trickle or solitary midges), Simuliidae (black flies), Ceratopogonidae (biting midges), and Chironomidae (midges). Hennig (1973) considered Simuliidae plus Ceratopogonidae as sister to Chironomidae. Relationships of families within the 2 superfamilies are still uncertain (Yeates & Wiegmann 2005). Wood & Borkent (1989), in a widely cited phylogeny of the Nematocera based on morphological characters, placed Thaumaleidae basal to Simuliidae + (Ceratopogonidae + Chironomidae). Also in agreement with these conclusions were the studies by Borkent & McKeever (1990) and Oosterbroek & Courtney (1995). A molecular phylogeny by Beckenbach & Borkent (2003) also placed Simuliidae sister to the clade of Ceratopogonidae + Chironomidae, but the study did not include Thaumaleidae. There are, however, conflicting views. Saether (2000), using morphological characters, placed Simuliidae as sister to Chironomidae, with Thaumaleidae basal in Culicomorpha.
In a molecular study, Pawlowski et al. (1996) placed Thaumaleidae as sister to Simuliidae in a study based on the 28S RNA gene. Of interest also was the suggestion that evolution of the 2 families had been rapid, in particular that of Thaumaleidae. Of less significance, Miller et al. (1997) placed Simuliidae as sister to Dixidae, but the study suffered significantly from lack of Thaumaleidae in the taxa analysed. A Thaumaleidae + Simuliidae sister relationship was well supported by the molecular study of Moulton (2000). That relationship was again well supported by Bertone et al. (2008) who examined multiple nuclear genes from a wide sweep of lower Diptera. Indeed, they suggested a new superfamily for Thaumauleidae + Simuliidae, the Simulioidea.
Of relevance to this is that Mandaron (1963) in a study of eggs and larval instars of Thaumaleidae showed that the eggs are slightly triangular in shape. Adler et al. (2004) suggested that a distinctly triangular-shaped egg was unique to Simuliidae. Further, Mandaron (1963) showed that thaumaleids have 14–20 larval instars — very unusual for lower Diptera, where 4 is the norm. Is it surprising, then, that Simuliidae have been recorded as having between 6 and 11 larval instars, with 7 the mean number (Crosskey 1990; Colbo 1989). Not only that, but structures and chaetotaxy of the labrum of Thaumaleidae larvae appear homologous to those of the early instars of the primitive simuliid Crozetia Davies (Craig 1974; Craig et al. 2003; Craig 2005; Craig unpub. pers. obs.).
Wiegmann et al. (2011), in a major authoritative review of evolution of Diptera based on molecular and morphological evidence, placed Simuliidae + Thaumaleidae as sister to Chironomidae + Ceratopogonidae, in good concordance with much of the above previous work.
The family Simuliidae is overwhelmingly now arranged as 2 subfamilies (e.g., Takaoka 2003; Adler et al. 2004; Adler & Crosskey 2012). One, the Parasimuliinae, has but a single genus, Parasimulium Malloch, which consists of 4 species considered basal simuliids (Currie 1988, Moulton 2003, Adler et al. 2004). The other, the Simuliinae, consists of two tribes, the Prosimuliini, and Simuliini. Within the latter Crosskey (1990), Crosskey & Howard (1997), and Crosskey (1999) previously recognised only the genera Austrosimulium and Simulium, all others were placed in the Prosimuliini. Now, however, a more restricted interpretation of Prosimuliini is used with some genera from that subfamily now assigned to Simuliini (Adler et al. 2004; Adler & Crosskey 2012). Within Simuliini Simulium is the most taxon rich genus and is widespread. Although that genus and its segregates do not occur in New Zealand, they have reached New Caledonia, Fiji, Polynesia, Australia, Tasmania, and Norfolk Island (Takaoka 1996).
Composition and relationships of the endemic Simuliidae (Austrosimulium)
It was Tonnoir (1925) who noted that the simuliids of New Zealand and some of those in Australia formed a segregate distinct from the genus Simulium Latreille. In erecting the genus Austrosimulium, Tonnoir explicitly noted that adults of the segregate possessed 8 (rarely 7) articles on the antennal flagellum, and in his descriptions and figures drew attention to the presence of an interarm (basal) strut on the anal sclerite of larvae and the frequent occurrence of a horned condition in the pupal gill.
Austrosimulium has been well accepted by subsequent workers, the majority of whom afforded it generic status. Edwards (1931) was the first to recognise the possible relationship between a South American simuliid and Austro-simulium, but he considered the segregate was merely a subgenus of Simulium. He noted the double bend of wing vein CuA2, the anal vein A1 that curved but did not reach the wing margin, 8 antennal flagellomeres, and a normally developed hind tibia.
Smart (1945) on the basis of Edwards (1931) associated Austrosimulium with Gigantodax in the tribe Austrosimuliini.
The Australian Austrosimulium were dealt with in a series of major works by Mackerras & Mackerras (1949 et seq.), who extended our knowledge and definition of the genus. They recognised 3 endemic species-groups — mirabile Mackerras & Mackerras, bancrofti (Taylor), and furiosum (Skuse) — basing the species-groups on morphological character states from pupae and adults. They considered the New Zealand fauna to be related to the mirabile species-group. Dumbleton (1963b) using other pupal characters as well as those of cocoons, recognised that the australense and ungulatum species-groups were precinctive to New Zealand. Although there were 4 species undescribed, his 1964a: 36 (his Fig. 1) showed distribution in the South Island, pupal gill structure, and cocoons. He transferred 2 Australian species originally placed in the mirabile species-group by Mackerras & Mackerras (1949) into the ungulatum species-group (Dumbleton 1963b: 335, his Fig. 2). Thence, this latter group is the only one common for the two countries. Crosskey (1969) in a major reanalysis of simuliids, concentrated mainly from Africa, reaffirmed the validity of Austrosimulium within Simuliini, again noting the close relationship to Simulium Latreille s.l.
Dumbleton (1960) in an examination of previously unknown larval material of the then Austrosimulium anthracinum (Bigot), from Tierra del Fuego, was of the opinion that there was no strong affinity with Austrosimulium, but rather that A. anthracinum would eventually be assigned to Gigantodax Enderlein, or another genus. Wygodzinsky & Coscarón (1962), in a detailed character analysis of A. anthracinum and other South American simuliids, however, disagreed with Dumbleton’s conclusion. While recognising infrageneric segregates within Austrosimulium, they assigned it subgeneric status as Austrosimulium (Paraustrosimulium) anthracinum. Crosskey (1969), however, considered Paraustrosimulium should be considered a genus: later workers agreed (e.g., Gil-Azevedo & Maria-Herzog 2007; Coscarón et al. 2008; Adler & Crosskey 2012).
Dumbleton (1963b), in an assessment of relationships within Simuliidae, reexamined the question of placement of A. anthracinum. He was equivocal regarding its assignment to Austrosimulium, noting a number of apomorphic features not found elsewhere in that genus. He further noted that 2 Australian species, A. bancrofti and A. furiosum, formed a segregate with affinities to Paraustrosimulium. To resolve the problem of modifying the diagnosis of Paraustrosimulium to accommodate those 2 Australian species, in 1973 he erected the subgenus Novaustrosimulium for them, resulting in 3 subgenera — Austrosimulium, Novaustrosimulium, and Paraustrosimulium — as comprising the genus Austrosimulium.
Davies & Györkös (1988) described the 2 Australian species Paracnephia pilfreyi (as Cnephia) and Austrosimulium colboi and briefly discussed the provisional placement of these two unusual simuliids. There are unpublished notes by the authors (in possession of DAC) relating to that 1988 publication, which give a more detailed comparison of these 2 species to Australasian and South American simuliids. In the 2008 edition of the world black fly inventory Adler & Crosskey placed Paracnephia pilfreyi in the subgenus Procnephia Crosskey, but in 2009 considered it unplaced to subgenus and this has remained so (Adler & Crosskey 2012). Placement of A. colboi is equally uncertain and it is still unplaced to subgenus (but see Bugledich 1999), possessing a mixture of characters across current subgenera. Of note, however, is that the pupal gill of A. colboi is remarkably similar to that of the putative sister taxon to Austrosimulium, the South American Paraustrosimulium, having 2 annulated inflated horns and no filaments. Further, A. colboi males possess a well developed plate-like paramere (DAC, pers. obs.), similar to that of P. anthracinum and which is absent from Austrosimulium. We comment on this later (see Cladistic Analysis, p. 53).
Moulton (1997), in a general molecular overview of Simuliidae that included Australian members of Austrosimulium (Novaustrosimulium), Paracnephia Rubtsov (as “Cnephia”), and the South American Paraustrosimulium anthracinum, proposed a cautious hypothesis of phylogenetic relationships. Pertinent here was a lineage in which P. anthracinum plus A. colboi (unplaced to subgroup), was sister to Paracnephia pilfreyi. This was part of an unresolved clustering of “intermediate” simuliines that included other Paracnephia. The 2 Novaustrosimulium species, however, grouped 4 nodes below that lineage and were basal in the Simuliini. The lineage of Paraustrosimulium, Paracnephia, and A. colboi was supported in other scenarios he examined. After further consideration Moulton (2000) made no changes to the above scenario. There is no disagreement between the findings of Moulton and those of Davies & Györkös (1988).
However, the above placement of the 2 Austrosimulium (Novaustrosimulium) species is in some contradiction with morphological evidence (Adler et al. 2004). For example, Austrosimulium possesses a pedisulcus on the hind leg, normally associated with “higher” simuliines and which is lacking in “lower” simuliines. Moulton’s placement would require evolution of the pedisulcus more than once.
Moulton (2003) again attempted the reconstruction of relationships for the Prosimuliini and Simuliini. As in his preliminary work, a tentative “best estimate” of such relationships also placed Novaustrosimulium sister to the rest of the Simuliini. He suggested, however, that that might be the result of “long branch attraction” which can cause misplacement of lineages. His original grouping and placement of A. colboi, Paraustrosimulium anthracinum, and Paracnephia pilfreyi were again fully supported.
Gil-Azevedo & Maia-Herzog (2007) in a preliminary phylogenetic analysis of simuliid genera of the Southern Hemisphere, using morphology, showed strong support for the subgenera Austrosimulium + Novaustrosimulium as sister to P. anthracinum, with Cnesiamima atroparva (Edwards) sister to those. For the present we consider Paraustrosimulium and Austrosimulium to constitute related genera.
The simuliid fauna of New Zealand all belong to the subgenus Austrosimulium which also occurs in Australia. Subgenus Novaustrosimulium, however, is precinctive to Australia.
In his revision of Austrosimulium Dumbleton (1973) segregated New Zealand’s Austrosimulium species into an australense species-group and an ungulatum species-group, and these species-groups were both further subdivided. The species-groups and subgroups he erected still apply and have been further substantiated by morphological analysis and, with minor differences, molecular analyses (p. 61).
The australense species-group, which comprised the majority of species, was distinguished by the female lacking a basal tooth on the tarsal claw, the pupa lacking ocular setae, the cocoon lacking an anterior projection, and the larva with the accessory sclerite expanded on the semicircular sclerite. Constituents of the ungulatum species-group typically possessed in the female a basal tooth on the tarsal claw, a pupa with ocular setae, a cocoon with anterior projection(s), and the larva without the expanded accessory sclerite.
The 2 subdivisions of the australense group of species were the australense-subgroup (A. australense, A. longicorne) that have a shallow convex cephalic plate on the pupa, and the tillyardianum-subgroup (now comprising A. albovelatum, A. alveolatum, A. dugdalei, A. extendorum, A. fiordense, A. laticorne, A. multicorne, A. stewartense, A. tillyardianum) with a markedly concave cephalic plate. Within the ungulatum species-group, the ungulatum-subgroup (now comprising A. campbellense, A. dumbletoni, A. ungulatum, A. vailavoense, A. vexans) lack a horn on the pupal gill and the gill filaments are thick and stiff, and the semicircular sclerite of the larva has a slight expansion on its ends (larvae and pupae of dumbletoni and vailavoense unknown). The unicorne-subgroup (now comprising A. bicorne, A. tonnoiri, A. unicorne) have in females a small basal tooth on the tarsal claw, absent often in A. unicorne, possess a distinct horn to the pupal gill with numerous fine filaments, and the semicircular sclerite tapers finely with no expansion.
Early European references to New Zealand simuliids
The earliest European reference to New Zealand Simuliidae is that by Joseph Banks, botanist on James Cook’s first voyage (1768–1771). His journal entry for 30 March 1770 stated “… sandflies maybe exactly the same as those of North America… . Of these last however, which are most Justly accounted the curse of any countrey where they abound, we never met with any great abundance; a few indeed there were in almost every place we went into but never enough to make any occupations ashore troublesome, or to give occasion for using shades for the face which we had brough[t] out to defend ourselves from them” (National Library of Australia 2004a). This appears to be the first written use of “sandflies” for New Zealand simuliids. Beaglehole (1963, vol. 2: 6) provided a footnote to this entry by biologist Averil Lysaght (Thomson 2010) which stated “The sandflies are Austrosimulium spp.” As Beaglehole commented in another accompanying footnote, such a balanced account was no doubt due to Banks being unable to go ashore at Dusky and Doubtful Sounds, Fiordland as he wanted (see Beaglehole 1963, vol. 1: 473; and Cook’s journal (National Library of Australia 2004b)). The few landings made on this voyage were mostly during the middle of the day rather than early morning or before sunset, and they did not venture far inland.
On Cook’s second voyage (1772–1775) 6 1/2 weeks were spent at Dusky Sound, Fiordland, and the West Coast black fly, Austrosimulium ungulatum Tonnoir, came to their attention. Cook’s (1777: 99) journal entry for 11 May 1773 summing up the visit noted that “The most mischievous animals here, are the small black sand flies, which are very numerous, and so troublesome, that they exceed every thing of the kind I ever met with. Wherever they bite they cause a swelling, and such an intolerable itching, that it is not possible to refrain from scratching, which at last brings on ulcers like the smallpox”. Cook’s quote is provided in a slightly different form in White & Doubleday (1843: 190), and editing changes were made by Beaglehole (1961: 136–137) based on Cook’s manuscript journal rather than published account, which were repeated in Dumbleton (1973: 494), e.g., “sand flies” to “sandfly”, “very numerous” to “exceeding numerous”, and “Wherever they bite” to “wherever they light”. Beaglehole again provided a footnote prepared by Averil Lysaght that expanded Cook’s mention by explaining “Cook, it must be allowed, speaks with great moderation of this pest, writing as he was in pre-dimethylphthalate days. It was Austrosimulium sp., whose larvae breed in running water; the adults are not uncommon throughout New Zealand, but abound multitudinously in the Sounds district.”
Cook’s opinion was supported by the comment of (Johann) Georg Forster (1777: 135–136), a junior naturalist on that second voyage who wrote for Dusky Sound 3–5 April 1773: “Another rainy pause of three days followed this excursion, confining us to our ship, where a sort of little crane-flies (tipula alis incumbentibus), which had plagued us ever since our entrance into Dusky Bay, became remarkably troublesome during the bad weather. They were numerous in the skirts of the woods, not half so large as gnats or mosketoes, and our sailors called them sand-flies. Their sting was extremely painful, and often as the hand or face grew warm, caused a troublesome itching, the least irritation of which brought on a very violent swelling, attended with great pain. We were, however, not all equally affected; myself in particular, never felt any great inconvenience from them; others, on the contrary, suffered in a very violent degree, especially my father, who could not hold a pen to write down the common occurrences in a journal, and fell into a high fever at night. Various remedies were tried, but all proved ineffectual, except the simple unction with soft pomatum, and the constant use of gloves.” This journal entry of Forster appears to be the first written record that not all were equally affected by the New Zealand simuliids, even among family members.
There are numerous accounts of the travails of New Zealand’s early European travelers in dealing with biting A. australense (Schiner) in the North Island in the 1830s and 1840s. The account by Angas (1847: 21, 23; see frontispiece) is but one. Polack (1838: 319) noted that “The most disagreeable, in their acquaintance, is the namu, or sand-fly; these little insects are mischievously troublesome; they have no particular choice as to what part they alight on the human body—the forehead or the ankle. They contrive, with their minute invisible feelers, to make a small puncture, which soon swells, causing an itching almost intolerable. These diminutive flies are easily killed, but are seldom caught, until they are engorged with the blood of their victims. The namu are most numerous on the borders of streams or marshy places, and appear in myriads before rain. These insects are absolutely cruel to the ladies, whose apparel is of a less guarded nature to that worn by the opposite sex.” Yate (1835: 72) wrote “… with a small sand-fly, not larger than a flea, but very noxious—its bite is sharp, and leaves an unpleasant itching for many hours—and they are so numerous on the beach, and by the sides of creeks and rivers, as to become, at times, almost a pest: their bite is most virulent before rain.” This account was probably about A. australense in the Northland or Auckland area of the North Island. Others accounts are given in Te Ara – the Encyclopedia of New Zealand (Walrond 2009).
South Island accounts are mainly about the species A. ungulatum in the Fiordland area, in areas near where Cook landed in 1773 during his second voyage. Of note is an account of Carl Björk (1880–1952) who lived in Preservation Inlet, Fiordland (Dougherty 2010). He kept the simuliids at bay by periodically rubbing his face with a mixture of rancid butter and kerosene, or grease and Jeyes Cleaning Fluid! An observant and most informative account of vast numbers of simuliids biting on Pigeon Island in the Fiordland region is by pioneering conservationist Richard Henry (1896). He was caretaker of neighbouring Resolution Island, which in 1894 became a safe sanctuary for flightless native birds, for about a decade, through the efforts of the Otago Institute and the Otago Acclimatisation Society (Omerod 2010). In this newspaper article Henry related how he trapped tens of thousands of adults by applying corned beef fat to a warm iron chimney.
The depredations of female simuliids in New Zealand has not changed since those early days of exploration and settlement, but modern repellents work adequately provided all exposed skin is well covered when in areas of high numbers of flies, and remains covered using repeated applications as needed. In 1971 a television documentary “Once bitten …” was prepared by the Christchurch television section (CHTV-3) of the New Zealand Broadcasting Corporation, but it was not screened — images of the tourists being bitten in the Fiordland area, because they were not using repellent, were thought to be too graphic and would not be good for tourism; a copy of the script is in the NZAC archives. Nowadays a search of the internet’s “YouTube” with the search string “sandflies New Zealand” will show that many people are still bitten and react badly to the bites.
A recent popular account regarding New Zealand sandflies is by Babirat (2011). Good general information is given, as well as some personal experiences of the biting.
Common names
Dumbleton (1973) discussed the use of the name “sandflies” by the naturalists and crew on Cook’s voyages. Elsewhere in the world simuliids are usually referred to as “blackflies”, “black-flies”, or more so now, “black flies”. Crosskey (1990) examined the use of those terms closely and Adler et al. (2004) listed some 28 common names for simuliids in North America. A worldwide “Blackfly Vernacular Names” can be found at http://www.blackflies.objectis.net/NamesZW/. The Oxford Dictionary defines “sandflies” as a small fly or midge, especially one belonging to the genus Simulium, and cites the use of the common name in this sense in Anson’s (1748) “Voyage around the World”. This common name probably originated because of the frequent abundance of biting Simuliidae on beaches. Crosby (1973b) noted that it is not at all clear that Anson was referring simuliids. The main problem with use of the term “sandflies” is that elsewhere in the world this is used to refer to biting Psychodidae, often of medical importance because of transmission of disease organisms. Still, the usage has persisted in New Zealand where “sandflies” is the universally employed common name for these insects. This causes no confusion, since there are no biting Psychodidae present in New Zealand, and though there is a single small biting midge (Ceratopogonidae) of localised distribution on sandy beaches, it is not sufficiently widely known to have acquired a common name.
Early collections of New Zealand simuliids
As Dumbleton commented, specimens of Simuliidae collected in New Zealand may have been present in insect collections that reached England at the end of Cook’s voyages, but there is no record of this. The reference by Forster (1777) to the Dusky Sound pest of the second voyage as “a sort of little crane flies (tipula alis incumbentibus)” suggests that some entomologist had seen and attempted to classify them. We consider it is unlikely this entomologist was Fabricius, who examined the insect collections made during all three of Cook’s voyages, as it would have been expected he would use the generic name “Culex” for them as he had done for other simuliids. For example, Fabricius (1775) listed 2 simuliid species on pages 800–801 under “Culex”; on pages 751–756 he listed 56 species under the genus “Tipula”: species 1–23 were under the grouping “Alis patentibus” and the remaining species 24–56 were under the grouping of “Alis incumbentibus”; none of the species in this latter grouping was a simuliid.
The first simuliid specimens from New Zealand of which there are extant specimens were presented to the British Museum by Dr Andrew Sinclair, presumably as accession [18]45-61. Walker (1848) listed these specimens in such a manner (“a” and “b”) that it appeared only 2 specimens were received in total (Dumbleton 1973: 495). The locality for “a” was recorded as New Zealand only, and no pinned specimens can be located at BMNH that can be attributed to this record (T. Howard (BMNH) pers. comm.). However, the “b” entry stated the locality was the Bay of Islands, and we were informed by T. Howard (pers. comm.) she had located the Walker “b” entry and found that in fact it referred to a pill-box and not a single specimen. With the unit tray containing the pill-box was a large note stating: “The pill box contains specimens reportedly collected at Bay of Islands (New Zealand) during the voyage of the “Erebus” and “Terror” and the basis for locality “b” cited by Walker (1848, List Dipt. Ins. Coll. Br. Mus. 1:113) attributed by Walker to White but never in fact published by the latter. See Dumbleton (1972, N.Z. Jl. Sci. 15:510) [caecutiens Walker nomen nudum]” (note [probably] by R. W. Crosskey, T. Howard, pers. comm.). Subsequent examination showed the pill-box contained about 450 specimens (Fig. 519–521). As Dumbleton (1973) correctly reported, Walker (1848) attributed authorship of the name Simulium caecutiens to White in the “Zoology of the Voyage of H.M.S. Erebus and Terror”. The name caecutiens, however, was not used by White (1846) in the Insecta part of that work, but may have been a manuscript name given to Walker by White. Our further checking showed that only 5 Diptera species — but no simuliids — were recorded in the second part of the Erebus and Terror publication by Butler (1874; Rye 1876). Schiner (1868) referred to “caecutiens”, attributed the authorship to Walker, and stated that to his knowledge no description of the insect existed. The name caecutiens is, therefore, a nomen nudum based on the Sinclair specimens. The Erebus and Terror were at the Bay of Islands 14 August–23 November 1841, and Sinclair arrived there from Australia on the Favorite on 24 October and collected with Hooker (Molloy 2010). It is not clear whether Sinclair gave specimens to his colleagues on the ships, but we consider this unlikely as no simuliid specimens were listed by White & Doubleday (1843). Some collections of the Erebus and Terror were sent back from the Falkland Islands on HMS Arrow after April 1842, but the Erebus and Terror did not get back until late 1843. We consider the caecutiens specimens were most likely collected in 1844 and presented to the British Museum in 1845 (see australense p. 104). On grounds of its greater abundance and biting habit, Dumbleton (1973) stated it seemed likely that of the two species known to occur in the locality the specimens were probably A. australense, rather than A. longicorne, and this has been well confirmed.
Specimens of the first New Zealand species to receive a valid name were collected at Auckland in late 1858, at the time of the visit of the Austrian ship Novara, and described by Schiner (1868) as Simulia australensis. The collector was not given, but we consider it was Sinclair (see australense p. 104). Specimens of a second species were collected on the Auckland Islands during a German Transit of Venus expedition in 1874 and subsequently described by Mik (1881) as Simulium vexans. The accounts of australense published by Hudson (1892) and Marshall (1896) added nothing new except Marshall’s and later Hutton’s (1902) observation that the antennae had 10 divisions (8 flagellomeres).
Studies on New Zealand simuliids since 1920s
The extensive studies of Tonnoir (1925) on the New Zealand and Australian Simuliidae resulted in a much more detailed knowledge of the structure and habits of all stages of the New Zealand Simuliidae and established the base for all later work. Tonnoir’s work was directly aimed at obtaining information that might be used to control the bothersome “sandflies”. Tonnoir (1925) found it impossible to separate the adults of some of the New Zealand species of Austrosimulium, although they were readily separable in their pupal stages.
The structure of the pupal respiratory organ of three of the New Zealand species was later studied by Pulikowsky (1929) in specimens supplied by Tonnoir. The work of Mackerras & Mackerras (1949 et seq.) while not concerned directly with the New Zealand simuliid fauna, established the existence of three species-groups in the Australian Austrosimulium fauna and thus provided valuable reference points for the recognition and definition of the species-groups present in New Zealand.
In the early 1950s there was interest from the Department of Agriculture in establishing myxomatosis virus to control introduced rabbits (Miller 1952b; and see p. 21). This interest in simuliids as potential disease vectors again focused attention on the need for accurate identification of the females of the various species of Austrosimulium which might serve as vectors for this or other virus diseases of man and animals that might gain entry to New Zealand. Dumbleton (1973) was able to separate the females of the 5 species in the ungulatum species-group, but had similar difficulties to Tonnoir in separating the adults of 5 of the then described 7 species of the australense species-group.
Also in the late 1950s pesticides were tested for controlling simuliids by Entomology Division, DSIR (Anon 1961), at which time it was commented “Experiments show the most satisfactory pesticide is DDT in a 5 per cent. diesel oil solution, which is applied to the stream water in spring and one month later.” It was stated that care was needed in its use so as to not affect fish or fish food.
In spite of persistent search, Tonnoir was unsuccessful in discovering the breeding place and early stages of A. ungulatum, the principal pest species in the South Island, and the feasibility of controlling its breeding could not be assessed until this was done. Although Tonnoir collected in many localities, he devoted little or no attention to the southern half of the South Island or the higher elevations of the Southern Alps and this deficiency was one that Dumbleton sought to remedy (Dell 1951). Dumbleton (1973) later found the characteristic habitat of A. ungulatum to be smaller streams under heavy shade in the forest, and immature stages were never found in high density: we concur with these observations, and note obvious difficulties involved in effective control of pestiferous populations in such situations.
With this present work, the North Island can now be considered to be well collected with a good understanding of the distribution of taxa that can currently be recognised morphologically. The South Island is also mainly well collected, but large areas of Fiordland are still to be explored, as are the high altitudes of much of the Southern Alps which may harbour new taxa of relatively restricted distribution similar to A. unicorne Dumbleton. Even with the surveys by Chadderton (1988, 1990), the southern parts and higher altitudes of Stewart Island are still basically terra incognita, in contrast to Campbell and Auckland Islands which we consider well collected. However, at both the molecular and cytological (chromosome) level, our knowledge of New Zealand simuliids remains at an early exploratory stage.